WHITE PLAINS, N.Y. — New government data showing an 8% to 16% drop in folate levels in young women is "very disturbing" and should prompt fortification of grain products at higher levels, according to the March of Dimes. Fortification with folic acid has been shown to help prevent neural tube defects (N.T.D.s).
The March of Dimes’ comments followed the Jan. 5 release of a detailed report on folate status in women of childbearing age published in the "Morbidity and Mortality Weekly Report," a publication of the Centers for Disease Control and Prevention (C.D.C.).
As part of their study, C.D.C. researchers, led by Dr. Joseph Mulinare, measured the folate levels in the blood of about 4,500 non-pregnant women between the ages of 15 and 44 from 1999-2000 through 2003-04. Their findings showed significant declines in folate levels across the three major ethnic groups in the United States, marking the first time a decline has been seen since the government mandated the fortification of enriched grains with folic acid in 1998.
The largest decrease, 16%, was noted among non-Hispanic whites, although non-Hispanic black women continued to be the ethnic group with the least folate in their blood, the C.D.C. said.
The C.D.C. said changes in laboratory techniques or sampling biases between survey periods were unlikely to account for the declines in folate levels in the report, instead pointing to several possible explanations, including:
• Changes over time in the proportion of women taking supplements containing folic acid;
• Decreased consumption of foods rich in natural folates or foods fortified with folic acid;
• Variations in the amounts of folic acid added to enriched grain products since fortification was mandated; and
• Increases in risk factors associated with lower folate concentrations such as obesity.
But the C.D.C. said evidence to support the explanations is mixed.
"With the exception of an increase in 2004, no substantial change was observed during 1995-2005 in the proportion of women of childbearing age who reported using a dietary supplement containing folic acid," the C.D.C. report noted. "Slight and conflicting changes in U.S. food consumption patterns have been noted; these include lower fruit and vegetable intake during 1999-2000 than during 1994-1996 but increased consumption of whole grains since 1970.
"In a 2005 survey, approximately 26% of women aged 18-45 years reported dieting during the preceding six months, and approximately 27% of dieters reported following low-carbohydrate diets; such diets might result in reductions in the amounts of fortified foods consumed. Another analysis also suggests that the mean folate content of certain enriched breads might have been reduced during 2000-03; other enriched cereal-grain products were not tested in this analysis. Finally, the prevalence of obesity among women aged 17-49 years increased from 21.8% during 1988-1994 to 32.3% during 1999-2000."
In response to the C.D.C.’s findings, the March of Dimes said it would petition the Food and Drug Administration to double the required addition of 140 micrograms of folic acid per 100 grams of grain to cereals, bread, pastas and other foods labeled "enriched" to 280 micrograms.
"The M.M.W.R. findings are very disturbing," said Dr. Jennifer L. Howse, president of the March of Dimes. "Folic acid is the most important vitamin that women can take to help prevent serious birth defects of the brain and spine, and it’s most important that they start consuming it before they get pregnant and continuing into early pregnancy."
According to the March of Dimes, since the fortification of enriched grain products with folic acid began in 1998, the rate of N.T.D.s in the United States has decreased 26%. But Dr. Howse stressed that the U.S. can still do a better job in preventing the birth defects.
"F.D.A. has to take action to increase the level of folic acid in the food supply to move this highly effective prevention effort forward," she said.
In addition to petitioning for more micrograms of folic acid, the March of Dimes will recommend the U.S. Congress double the funding the C.D.C. gets for its national public and health professions education campaign designed to increase the number of women taking folic acid every day. The C.D.C. currently gets $2 million per year for the campaign.
Judi Adams, president of the Grain Foods Foundation, said one of the G.F.F.’s primary goals is to educate consumers about the important nutrition benefits of bread and grains. On Jan. 9, the G.F.F. launched a nationwide campaign with Susie Castillo, an announcer on MTV and the 2003 winner of the Miss USA competition, aimed at reaching women in their 20s and 30s as well as the Hispanic community.
"We have been sending this message via our spokesperson, Susie Castillo, as we have seen indications of this happening," Ms. Adams said of the C.D.C.’s findings on declining folate levels. "It was just a great confirmation of our important message about eating more enriched grain foods. All of the people who say you should only eat whole grains are obviously wrong."